* Heroes with strong area-of-effect damaging and/or disabling abilities will be able to intercept Underlord and his team when they exit from Fiend's Gate: Luna's Aghanim's Scepter upgraded Eclipse, Dawnbreaker's Solar Guardian, Axe's Berserker's Call, Mars's Arena of Blood, Jakiro's Macropyre, Dual Breath and Ice Path, Naga Siren's Song of the Siren, Razor's Eye of the Storm and Plasma Field, Lina's Light Strike Array, Broodmother's Spinner's Snare from Aghanim's Scepter, Elder Titan's Earth Splitter and Echo Stomp, Alchemist's Unstable Concoction and Acid Spray, Queen of Pain's Sonic Wave, Dark Seer's Wall of Replica and Vacuum, Venomancer's Noxious Plague and Poison Nova from Aghanim's Scepter, Oracle's Fortune's End and Rain of Destiny from Aghanim's Shard, Bloodseeker's Blood Rite, Enigma's Black Hole and Midnight Pulse, Shadow Fiend's Requiem of Souls, Batrider's Aghanim's Scepter upgraded Flaming Lasso, Firefly, Flamebreak and Sticky Napalm, Ancient Apparition's Ice Blast, Sand King's Epicenter, Sand Storm and Burrowstrike, Gyrocopter's Call Down, Ember Spirit's Sleight of Fist, Death Prophet's Exorcism and Silence, Monkey King's Wukong's Command, Crystal Maiden's Freezing Field, Muerta's The Calling, Medusa's Stone Gaze, Zeus's Nimbus from Aghanim's Scepter. Dark Willow's Bramble Maze, Pangolier's Swashbuckle, Grimstroke's Soulbind, Ink Swell and Stroke of Fate, Earthshaker's Echo Slam and Fissure, Puck's Dream Coil and Waning Rift, Winter Wyvern's Winter's Curse, Magnus's Reverse Polarity.

* Heroes with gap-closing abilities who attempt to use them for escaping Bloodseeker will suffer serious damage from Rupture: Phantom Assassin, Anti-Mage, Faceless Void, Riki, Slark, Spirit Breaker.

* Heroes who are strong against mobile heroes: Disruptor, Bloodseeker, Kunkka, Keeper of the Light.

* Bloodseeker's Thirst, Rupture, and huge AoE silence Blood Rite can fare well against Dazzle.

* Phoenix expends health to use its abilities, making it a good target for Thirst.
* Rupture deals heavy damage against Icarus Dive.
Additional:
* Although Blood Rite can be easily avoided, if it does hit, its lengthy silence and pure damage can be a severe punishment for a slow, unobservant, or simply unfortunate Phoenix.
* His Rupture can turn Icarus Dive into a suicide option, and it cannot be dispelled, meaning even if Phoenix completes a Supernova, choosing to Dive may just cut its health back down.
* And finally, due to Phoenix's health costs, too much careless ability spamming may just put Phoenix into Bloodseeker's vision through Thirst, making it a very tempting ganking target.

* Marci can destroy Supernova by herself with Unleash at any stage of the game.
* Phoenix is squishy hero with low armor and is very vulnerable for Rebound and Sidekick at the laning stage.

* Sniper's lack of mobility and escape mechanisms makes him one of the easier heroes for Bloodseeker to gank.

* Marci can be effective against vulnerable squishy heroes that cannot deal with heroes that jump onto them - Sniper, Drow Ranger, Lina, Rubick, etc.

* As a spellcaster, silences will nullify him entirely. Some notable examples are Death Prophet, Drow Ranger, Bloodseeker, Disruptor and many others.
* Doom, as usual, fits this description nicely.

* Marci on the midlane will win the laning phase against Zeus almost every time, as her powerspike at level 6 will decimate Zeus' low health pool and force him to stay far back.
* Even before level 6, Dispose and Sidekick can easily take half of Zeus' health if he is in range of Dispose.

* Windrun triggers the damage from Rupture.
Additional:
* Rupture turns Windranger's mobility against her.
* Blood Rite's silence makes Windranger totally useless, since she's extremely reliant on abilities.

* Untouchable doesn't work against Unleash, as Marci gains 1000+ attack speed for the fury combo.
* Enchantress' low health makes her a fragile target for Marci's damage blasts.
* Marci can use Rebound on one of her enchanted creeps to easily reach the Enchantress and negate the bonus damage dealt by her Impetus. It helps that most of her best creeps have a low attack range, creating a makeshift bridge towards their master.

* Thirst detects Mirana or her ally at low health during Moonlight Shadow.
* Rupture deals high damage when Mirana uses Leap.
Additional:
* Rupture can quickly kill Mirana if she tries to Leap away.
* Thirst detects Mirana and her allies during Moonlight Shadow.

* Sprout can't stop her to Rebound.
* Treants can be used as targets for Rebound and Dispose as well.

* Rupture and Blood Rite locks down Timbersaw, preventing him from escaping with Timber Chain. However, Timbersaw may reflect a good deal of damage with Blade Mail.

* Bloodseeker is one of the hardest counters to Slark.Thirst prevents Slark from healing in lane with Shadow Dance and may set him up for a kill while in the jungle,or retreating.
* Rupture will deal damage during Pounce.
* Dark Pact cannot dispel Rupture, preventing Slark from escaping ganks.
Additional:
* Thirst stops Shadow Dance's passive health regeneration if Slark's current health is below the Thirst's visibility threshold.
* Rupture effectively diminishes Slark's mobility in battle, leaving him susceptible to AoE stuns or forcing to teleport out of the fight.

* Primal Beast's abilities require movement to deal damage, making Rupture potentially deadly and debilitating. Furthermore, its initial damage based on the target's current health is devastating to a full-health Primal Beast with his high strength gain and thus high HP.
* Due to his reliance on spells, Primal Beast is vulnerable to Blood Rite's powerful silence without items to counter it.

* Rupture deals extra damage to Magnus during Skewer or Force Staff, preventing him from escaping or counter-initiating, forcing him to invest on a Linken's Sphere.

* Blood Rite prevents Queen of Pain from escaping with Blink.
* Blink will trigger the extra damage from Rupture.
Additional:
* Blood Rite silences her, preventing her from initiating or escaping.
* With Thirst, even if she Blinks away, Bloodseeker can catch right up to her.
* Rupture will heavily damage Queen of Pain if she tries to Blink away.
* She is, however, one of the few heroes who can avoid the damage from Rupture if she successfully blink-walks.

* Thirst detects Riki whenever his health is low.
* Rupture does large damage when Riki uses Blink Strike.

* Skeleton Walk is not enough to outrun Bloodseeker, and is detected by Thirst.
* Because of his low health and high damage output, Clinkz will get obliterated by Blade Mail
Additional:
* Thirst reveals Clinkz if he tries to escape with Skeleton Walk with low health. It also allows Bloodseeker to match or exceed Clinkz's speed.
* Rupture negates the mobility provided by Skeleton Walk in any attempt to escape or reposition in fights.
* Bloodseeker can easily build items to counter Clinkz, including Talisman of Evasion upgrades, Blade Mail, and armor items.

* Huskar is often at low health, providing large Thirst bonuses.
* Life Break triggers Rupture's damage.
Additional:
* Huskar is often at low health, providing large Thirst bonuses to Bloodseeker.
* Life Break can trigger Rupture's damage.
* A self applied Bloodrage together with Blademail means it's almost suicidal for Huskar to jump on Bloodseeker with Life Break

* Thirst allows Bloodseeker to see where Io relocated to, should either Io or the tethered hero have low health.
* Rupture forces Io to stay in place, preventing it from using the Tether bonus movement speed to escape.

* Blood Rite makes Ezalor chose between getting off Illuminate or getting silenced for a while, as Illuminate is a channeled ability.
* Blood Rite's silence can completely take Ezalor out of a teamfight, as he relies on his abilities to be useful.
* Keeper of the Light's only mobility source, his high movement speed (via his high base movement speed and through spirit form), is entirely countered by Rupture.

* Nether Swap triggers extra damage from Rupture.
* Blood Rite sets up while Vengeful Spirit using her Nether Swap within a timed correctly.

* Blood Rite can potentially force him to activate Black King Bar prematurely, before pulling off a Black Hole combo.
* Bloodseeker can find an Enigma out of position and Rupture him, making it difficult to initiate properly in a team fight, as it pierces through Black King Bar.

* Every Meepo clone adds to Thirst's bonuses.
* Bloodseeker can chase down retreating clones when Meepo tries to cycle weaker clones away from combat.

* Bloodseeker is not affected by slows when he is affected by Thirst.
* If he sees Chain Frost is targeting him, he can easily isolate himself with the movement speed buff from Thirst so that it stops bouncing around.
* Lich heavily relies on his abilities to contribute to team fights, making Blood Rite effective against him.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

* Heroes that can maintain vision on Monkey King can see when he uses Tree Dance: Bloodseeker, Treant Protector with Eyes In The Forest, Sniper, Weaver

* Heroes with long-lasting, undispellable debuffs will pinpoint the true Naga Siren: Spirit Breaker, Bloodseeker, Witch Doctor.

* Heroes with good mobility to avoid Jakiro's abilities and with good chase to punish Jakiro from pushing a tower: Bloodseeker, Ember Spirit, Juggernaut, Phantom Assassin, Weaver.

* Bloodseeker's Rupture forces Slardar to stay still during fights, preventing Slardar from using Guardian sprint to move in and out of fights. This takes away the ability to initiate and re-initiate with Slithereen Crush's low cooldown. Due to the increased move speed from Guardian Sprint, Slardar can lose health at about 160% the rate of normal heroes while under Rupture. Bloodseeker's Thirst also gives him enough move speed so that he's one of the few heroes who can outrun or catch up to a Slardar during Guardian Sprint.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

* Heroes with gap-closing abilities who attempt to use them for escaping Bloodseeker will suffer serious damage from Rupture: Phantom Assassin, Anti-Mage, Faceless Void, Riki, Slark, Spirit Breaker.

* Marci can be effective against vulnerable squishy heroes that cannot deal with heroes that jump onto them - Sniper, Drow Ranger, Lina, Rubick, etc.

* Heroes with fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, Earth Spirit, Dark Seer.

Additional:
* Rupture can deal a lot of damage to either a surged Dark Seer or his allies and prevent the target from getting into position.

* Heroes with gap-closing abilities who attempt to use them for escaping Bloodseeker will suffer serious damage from Rupture: Phantom Assassin, Anti-Mage, Faceless Void, Riki, Slark, Spirit Breaker.

* Heroes with fast movement abilities will suffer huge damage when afflicted by Rupture: Spirit Breaker, Earth Spirit, Dark Seer.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

Additional:
* While Burrowing, Nyx is an easy target for a Blood Rite, and his only way to counter it is a well-timed Spiked Carapace.
* Thirst is always a threat to Nyx Assassin, hindering his attempt of escape using Vendetta and rendering him unable to surprise Bloodseeker's allies.
* Rupture also prevents Nyx Assassin from escaping with Vendetta, as it forces him to stay still.

* Marci can be effective against vulnerable squishy heroes that cannot deal with heroes that jump onto them - Sniper, Drow Ranger, Lina, Rubick, etc.

* Heroes with invisibility will be detected by Thirst when they have low enough health: Bounty Hunter, Templar Assassin, Riki, Clinkz, Weaver, Treant Protector, Nyx Assassin.

Additional:
* Rupture can turn Bounty Hunter's mobility against him, and prevents him from escaping with Shadow Walk due to the potentially heavy damage.
* Thirst can prevent Bounty Hunter from escaping with Shadow Walk should Bounty Hunter's health become low enough, as it provides True Sight.

* Bloodseeker's Rupture turns Night Stalker mobility against him and Thirst grants movement speed bonus and vision prevents Night Stalker from initiating and re-initiating.

* Rupture will fully damage Void Spirit during his ultimate, removing his main escape mechanic during fights and his way to disrupt them heavily.
* Blood Rite will force Void Spirit to use Dissimilate or Astral Step or be silenced. In the latter's case, it can be dangerous when combined with Rupture.

* Bloodseeker's Rupture shows a clear red trail effect on the real Phantom Lancer.
* Heroes with undispellable debuffs will help identify the real Phantom Lancer through visual effects or debuff indicators, provided that it was cast on the real Phantom Lancer to begin with:
* Doom's Doom marks Phantom Lancer with a highly visible effect, and also silences and mutes him.
* Bloodseeker's Rupture shows a clear red trail effect on the real Phantom Lancer.
* Ancient Apparition's Ice Blast will only debuff Phantom Lancer and not his illusions.
* Grimstroke's Soulbind is undispellable.
* Shadow Demon's Demonic Purge is undispellable.
* Monkey King's Jingu Mastery is undispellable and puts a big yellow Mark over his head.

* Marci can be effective against vulnerable squishy heroes that cannot deal with heroes that jump onto them - Sniper, Drow Ranger, Lina, Rubick, etc.

* Rebound allows her to jump in or out of the Arena Of Blood. She can save her allies from the Arena with Dispose as well.

* Shukuchi will trigger extra damage from Rupture.
* Shukuchi's invisibility is detected by Thirst.
* Time Lapse cannot dispel Rupture, preventing Weaver from escaping ganks. However, smart Weaver will buy Linken's Sphere to counter this problem for him.
Additional:
* Rupture is particularly crippling against Weaver, who relies on high movement speed from Shukuchi to fight and escape, and it cannot be dispelled by Time Lapse.
* Thirst detects Weaver through Shukuchi whenever his health is low.
* Blood Rite combined with Rupture forces Weaver to either take damage from the latter, or to get silenced for a long duration.

* Blood Rite prevents Anti-Mage from escaping with Blink.
* Blink will trigger the damage from Rupture.
* Both Blood Rite & Rupture are pure damage which can bypass Counterspell.

* Rupture works through Rolling Thunder and Swashbuckle, greatly reducing Pangolier's mobility.
Additional:
* Thirst provides constant sight and speed to Bloodseeker, allows him to catch up a fleeing Pangolier through all of his mobility.
* Rupture is a great threat to Pangolier, causing him to take heavy damage if he uses Swashbuckle and especially Rolling Thunder, forcing him to stop his ultimate prematurely, or keep rolling to his death.

* Heroes with silences : Bloodseeker, Riki, Silencer.

* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.
Additional:
* Rupture completely negates Lycan's high mobility.
* All of Lycan's summons are good sources of healing with Bloodrage.